10+ Random Facts About 'It's Always Sunny In Philadelphia' Fans Should Know

Rob McElhenney can be credited with literally dreaming up the concept of It's Always Sunny.

Apparently, he had a nightmare about a man with cancer and his insensitive friends.

And thus the show was born!

Episode 4 of season 1, "Charlie Has Cancer" follows the same storyline as the original pilot episode.

Charlie Day is married to Mary Ellis, who plays The Waitress.

Rob McElhenney and Kaitlin Olson, Mac and Dee respectively, are married.

Glenn Howerton married Jill Latiano who briefly appeared in The D.E.N.N.I.S. System.

For the underwater sequence of the season 11 finale, Devito had to be weighed down as he was too buoyant.

When it was time to resurface he needed assistance from [safety divers](https://www.itsalways.com/danny-devito-drowned/.

In season 7 McElhenney deliberately put on 50 pounds to subvert the trope of sitcom characters getting more attractive over the years.

To do this he had to eat a whopping 5,000 calories a day!

You may not have heard of her but Reid helped develop the show and originally played Dee.

She was dating McElhenney at the time but when they broke up she was dropped from the show.

Dee was originally the voice of reason for The Gang.

But after Olson's performance as the Dee we all know and love today, the writers were pushed to continue writing her that way.

This inappropriately close family are based on Day and McElhenney's memories of two different families they knew in their youth.

Ever wondered what's up with the credits?

It's Day, McElhenny and Howerton speaking backward!

Season 1's secret message is 'You're stupid for playing this forward.'

Olson revealed that she and her husband's characters will never date as their characters are too revolted by each other.

Now that's romance.

Howerton didn't want his characters name to be associated with his, due to the road Dennis would go down.

His increasingly sociopathic behavior has been deliberately cultivated since the first episode.

GoT showrunners David Benioff and D.B. Weiss wrote the episode "Flowers for Charlie", where he is the lab rat for an experimental drug and briefly becomes super smart.

It was supposed to be about 3 actor friends in LA struggling to make it in the industry.

They later decided to move it to Philadelphia where the characters own a dive bar.

The inspiration for Charlie's green bodysuit was a friend of Day's who used to wear a similar suit to Eagle games in real life!

In season 4 when Dee runs into a car headfirst, it's all Olson.

She had a stunt double on set but took a blow for the sake of comedy.